The muscles of the lower back help stabilize, rotate, flex, and extend the spinal column, which is a bony tower of 24 vertebrae that gives the body structure and houses the spinal cord.

Axial MRI of the Lumbar Spine - T2 weighted image at the L4 level. On this view centered over the L4-L5 disk, one can see well the cauda equina surrounded by CSF (note that CSF is bright on ...